I seem to be having a problem with bonding under Debian
Lenny, but I am not sure exactly what the problem is.

I have two servers and each server has two gigabit network
cards. We have two gigabit switches that we use so that we have failover should
one die. I matched both eth0’s to switch0 and both eth1’s to switch
one. I then bonded the eth’s together on both servers. I posted how I did
it below just in case I screwed something up. Once I did the bonding,
everything looks to be OK. I can ping out and I can ping the hosts from other
systems. I pulled the network plug from one of the cards and watched that the
failover worked as it should. Then I plugged it back in and removed the other.
Everything worked as I thought it should; I am not an expert at bonding but I
have used the same method a few times now without problem.

Well I went on about my business and soon complaints began
to come in that one server was much slower then the other. :-/

I began investigating and sure enough, one system is slower.
Transferring a 1GB file across the network, I easily maintain ~38-40M/s on the
first host and I usually top out around 15-18MB/s on the other. Ifconfig shows
that both cards are set to the proper speed (txqueuelen:1000) but it isn’t
behaving like should be. Worse is when I do a watch or htop or something else
that updates I can notice the lag. For example, I have ssh’d into the
system and have htop running right now; it is supposed to update every 2
seconds. It works like it should for a short time but then every once in a
while the screen freezes for about 10 seconds, then everything updates all at
once and continues its 2 second update interval.

I thought it was the network cards, so I disabled the
bonding and tested each of them. I get gigabit speeds individually. Rebonded
the cards and I am back to the slow speeds. I turned off the system to see if
there was physical damage or something (found nothing) and when I brought it
back up I saw this in the logs:

Oct 30 11:53:06 Hostname kernel: [ 13.012292]
tg3: eth1: Flow control is off for TX and off for RX.

I see the tg3 messages in the first server, but I don’t
see the bonding warnings. My guess is that the bonding is somehow screwed up
and stuck on 100Mb/sec and doesn’t update when the cards go to 1000Mb/sec.
I tried to find an answer via google but did not find anything that seemed
useful to me. I see others have had this problem, but I found no solution that
helped me.

I don’t know why one works and the other doesn’t.
They should be pretty similar in setup and configuration as I didn’t do
anything drastically different when I built them.

Any help would be appreciated.

Thanks!

Chris Stackpole

How I did the bonding:

# apt-get install ifenslave

# vi /etc/network/interfaces

auto lo

iface lo inet loopback

auto bond0

iface bond0 inet static

address
10.3.45.3

netmask
255.255.255.0

network
10.3.45.0

broadcast
10.3.45.255

gateway
10.3.45.251

dns-nameservers
10.1.1.5 10.1.1.6

dns-search
mydomain.com

up
/sbin/ifenslave bond0 eth0 eth1

down
/sbin/ifenslave -d bond0 eth0 eth1

Then I restarted (yeah I know I could have just reset the
network but I restarted).

When it was back up ifconfig shows bond0, eth0, eth1, and lo
all correctly.